A team of Dallas scientists is looking for about 160 seniors interested in getting fit who will consider being part of a $15 million study that may also lead to healthier brain function.

UT Southwestern Medical Center and Texas Health Resources are recruiting volunteers for a national clinical trial that aims to map out a prevention for Alzheimer’s disease by exploring the role that better heart health plays in staving off the progressive, irreversible and costly condition.

Some study participants will be treated with current medications that lower high blood pressure and cholesterol, conditions that are risk factors for Alzheimer’s and stroke-related brain damage. But it’s not just drug therapy that North Texans who make the two-year commitment could get prescribed.

“We give exercise as a medicine,” said Rong Zhang, neurology professor at UT Southwestern’s O’Donnell Brain Institute and lead researcher of an interventional trial that includes six U.S. sites.

About half of those who join the study locally will be randomly assigned to have their gym memberships paid for and to be matched with an exercise physiologist who will personalize their exercise programs and visit them regularly to keep them on track.

Observational studies over the past two decades have shown a correlation between cardiovascular risk factors and Alzheimer’s disease. The new study aims to determine whether patients should be given more specific clinical recommendations than just to exercise and control their blood pressure and cholesterol levels.

“The next question is, exactly how much should you do?” Zhang said. How much aerobic exercise is needed, and what type works? How far should blood pressure and cholesterol be lowered exactly?

“That’s where there is a knowledge gap. Our goal is to answer these questions head on,” he said.

The study is one of several ways Texas researchers are delving into the intricacies of the human brain. There is national demand for neurological research to help curb the $1.5 trillion impact that brain conditions are having on the nation’s gross domestic product — a problem that is forecast to get worse.

The number of Americans with Alzheimer’s disease or mild cognitive impairment is expected to more than double, from just over 6 million in 2017 to about 15 million in 2060, according to projections published this month in the journal of the Alzheimer’s Association.

In 2017, nearly 47 million people had early signs of the conditions, though their symptoms may not necessarily progress to a diagnosis.

Over the summer, the National Academies of Sciences, Engineering and Medicine issued a report noting that despite an array of advances in understanding cognitive decline and dementia, the evidence on interventions remains “relatively limited” and has “significant shortcomings.”

The report recommended more research on three interventions for which results have been encouraging but inconclusive: cognitive training, blood pressure control and increased physical activity.

The latter two are where the current study hopes to intervene. “The trial wants to understand if doing something good for the heart means something good for the brain,” explained Zhang.

It will test how improved heart health — through exercise, drug therapies or both — will affect the flow of blood that carries oxygen and other nutrients to the brain.

As people age, the vessels that allow the blood’s passage get clogged and lose plasticity, kind of like what happens to a water pipeline running through an old home, Zhang said.

Exercise and drug therapy, he said, can reduce oxidative stress and essentially “clean the pipeline.”

The North Texas researchers are collaborating with others from the University of Kansas Medical Center, Washington University School of Medicine, Pennington Biomedical Research Center in Louisiana and Michigan State University on the Risk Reduction for Alzheimer’s Disease, or rrAD, study, which launched in late 2016.

The goal is to enroll 640 people nationwide who are between ages 60 and 85.

Participants are randomly assigned to one of four action plans. One requires taking cholesterol and blood pressure-lowering drugs. A second requires only exercise. The third combines exercise with drug therapy. The fourth simply allows the patient to follow their primary care doctor’s recommendations.

To qualify, residents must have high blood pressure and have already experienced a noticeable decline in memory. Or, they must be considered high-risk, meaning they have a family history of dementia — such as a diagnosis in a parent or sibling.